In bolted tank radiator manufacturing practice, it is customary to bolt up the complete assembly and then conduct a leak test. If the radiator has leaks in the corners that are difficult to repair, the side channels are removed and reinstalled after the leak is repaired.
In some cases, the channels are not installed, but the bolts that attach the channels to the tanks are installed. This provides a sealed joint between the and tank and headsheet. After leak testing and repair, if necessary, the bolts holding the tank in the channel area are removed and the channel installed.
These practices are undesirable for the reasons that (1) the sealed joint between the tank and gasket can be opened or unsealed, producing a subsequent leak, or (2) the installation of the channel may, at times, prestress the end tube-to-headsheet joint and break the seal between the tube and the headsheet. Partially adjustable side channels have been used to eliminate the possibility of prestressing. However, in the event of leaks, the channels must be completely removed to permit the repair work.
In both cases, the operation of removing the channels for repair purposes, or removing the bolts to install the channel after test is time consuming.